Socket-key for electric-lamp sockets.



PATENTED APR. 2, 1907.

APELIOATION FILED JULY 5, 1906.

Av e m a M UNITE STATES PTENT FFICE. PHILIP L. SYLVESTER, or SORANTON, PENNSYLVANIA, ASSIGNOR TO THE SCRANTON BUTTON COMPANY, or SCRANTON, PENNSYLVANIA, A con- PORATION OF PENNSYLVANIA SOCKET KEY FQR ELECTRflG Li-KFWP SOCKET-Sr Specification of Letters Patent.

Patented-April 2, 1907.

Application filed uly fl 324.785.

To (all 1117mm it may concern:

Be it known that I, PHILIP L. SrLVEs'rER, a citizen of the United States, residing at Scranton, in the county of Lackawanna and State of Pennsylvania, have invented certain new and useful Improvements in Socket-Keys for Electric-Lamp Sockets, of which the following is a specification.

My invention relates to improvements in keys for use in connection with incandescent electric-lamp sockets whereby the breakage, splitting, or cleavage of the molded insulating-material pieces of such keys is prevented.

In.the accompanying drawings, Figure 1 is a side elevation of a socket-key. Fig. 2 is a central section through the same on the line 2 2 of Fig. 3. Fig. 3 is a similar view on the line 3 3 of Fig. 1, and Fig. 4 is aperspective View of the metal stem of the key.

finger-piece of molded insulating material for socket-keys of the usual form, having a flattened head 1 and a shank or boss 2 thicker than the head. The stem B of the key consists of a metal rod or mandrel 3, having one end flattened, and by preference, though not necessarily, slotted, forming diverging tongues 4 4 and having ribs or lugs 5 5 projecting from the body of the rod'adjacent to said flattened portion but in planes at right angles to said portions. When the finger-piece is molded around the shank of the key, the flattened end 4 4 lies in the central plane of the head 1, while the ribs or lugs 4 extend in a plane at right angles to the central plane of'the head. The ribs or lugs 5 5 are preferably formed by swaging or pressing up the metal of the rod 3. Keys of this character are usually made by molding the fingeriece around a plain cylindrical metal ro having a flattened end; but with this construction it is found that the heads of the keys frequently split in the plane of the flattened end of the rod, and separate from the rod when subjected to the torsional strains incidental to turning on and off incandescent lights. The plastic material has a tendency to become laminated in the plane of the flattened end of the mandrel during the process of molding the head of the key. In the molding process a piece of plastic material is first pl acod on the lower die or mold, the flattened end is then placed on this piece of plastic material,then

another piece of plastic material is laced on the flattened end of the mandre and the upper die is then brought to bear upon the plastic material, which is subjected to heavy pressure between the dies. As the dies or molds come together the surplus plastic material is forced out between the dies, and the-lamination of the material is. caused by the lateral flowing of the material under pressure toward the edges of the dies,

during which the particles of material arrange themselves flatwise. This lamination makes the keys susceptible to easy cleava e in the plane of the head, and consequent y when the key is subjected to any undue torsional strain the finger-piece frequently splits in the plane. of the flattened end of the i 1 metal rod or mandrel. Referring to the draw ngs, A indicates a By providing one or more lugs or ribs upon the rod, each projecting at an angle to the plane of the head of the finger-piece, and

therefore at angle vto the laminations of said finger-piece, splitting of the fingerpiece is prevented. These ribs are preferably in the stem and thicker portion of the head and preferably at right an 'les to the flattened portion of the head, as s own, and the torsional strain of the head is transmitted to the mandrel largely through these tened ends may be omitted in someforms of keys.

Havingthus described my invention, what I claim, and desire to protect by Letters Patent, is-

1. A key for incandescentdamp sockets comprising a finger-piece of molded insulating material having a flattened head and a shank or thickened portion at one end of said head, and a metal stem or spindle embedded in said shank and having one or more ribs or projections embedded in the shank and extending at an angle to the central plane of said head.

2. A key for incandescent-lamp sockets comprising a finger-piece of molded insulatmg material having a flattened head and a shank 0r thickened portion at one end of said head, and a metalstem or spindle having a flattened end embedded in said flattened head and havingone or more ribs or projections extending at an angle to the plane of said end and embedded in said shank or thickened portion.

3. A key for incandescent-lamp sockets comprising a finger-piece of molded insulating material having a flattened head and a shank or thickened portion at one end of said head, and a metal stem or spindle having a flattened end embedded in said flattened head and having ribs projecting from oppo site sides of the shank at right angles to the plane of said end and embedded in said shank or thickened portion of the linger-piece. 20

In testimoni whereof I aliix my signature in presence of two witnesses.

PHILIP L. SYLVESTER. Witnesses:

SAML. H. STEVENS, C. A. BATTENBERG. 

